Comal and Hays Counties, Texas

Survey Area TX604• Texas

The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Comal and Hays Counties, Texas. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map Unit	Acres	Drainage	Hydro Group	Dwellings	Septic
Comfort-Rock outcrop complex, 1 to 8 percent slopes	154K	Well drained	D	Very limited	Very limited
Brackett-Rock outcrop-Comfort complex, 1 to 8 percent slopes	110K	Well drained	D	Very limited	Very limited
Rumple-Comfort, rubbly association, 1 to 8 percent slopes	106K	Well drained	D	Very limited	Very limited
Brackett-Rock outcrop-Real complex, 8 to 30 percent slopes	105K	Well drained	D	Very limited	Very limited
Real-Comfort-Doss complex, 1 to 8 percent slopes	44K	Well drained	D	Very limited	Very limited
Eckrant-Rock outcrop association, 8 to 30 percent slopes	33K	Well drained	D	Very limited	Very limited
Houston Black clay, 1 to 3 percent slopes	20K	Moderately well drained	D	Very limited	Very limited
Bolar clay loam, 1 to 3 percent slopes	16K	Well drained	C	Very limited	Very limited
Doss silty clay, moist, 1 to 5 percent slopes	16K	Well drained	D	Very limited	Very limited
Heiden clay, 3 to 5 percent slopes, eroded	16K	Well drained	D	Very limited	Very limited
Branyon clay, 0 to 1 percent slopes	13K	Moderately well drained	D	Very limited	Very limited
Krum clay, 1 to 3 percent slopes	13K	Well drained	C	Very limited	Very limited
Water	12K		D	Not rated	Not rated
Denton silty clay, 1 to 3 percent slopes	11K	Well drained	D	Very limited	Very limited
Sunev clay loam, 1 to 3 percent slopes	9K	Well drained	B	Not limited	Somewhat limited
Lewisville silty clay, 1 to 3 percent slopes	9K	Well drained	C	Very limited	Very limited
Real gravelly loam, 1 to 8 percent slopes	9K	Well drained	D	Very limited	Very limited
Purves clay, 1 to 5 percent slopes	8K	Well drained	D	Very limited	Very limited
Heiden clay, 1 to 3 percent slopes	7K	Well drained	D	Very limited	Very limited
Tinn clay, 0 to 1 percent slopes, frequently flooded	7K	Moderately well drained	D	Very limited	Very limited

Soil Orders in This Area

The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.

Mollisols

Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.

Vertisols

High-clay soils that shrink and swell dramatically. Fertile but challenging for foundations and septic systems.

Inceptisols

Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.

What This Means

Building & Foundations

About 97% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 97% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.